Flawed ReasoningDiff: Medium
Logic Breakdown
Passage Summary: The speaker claims that because there are no geckos in the area, there can't be any gnats, which means the area can't be wet.
Conclusion: The local climate must not be wet.
Reasoning: Geckos are found wherever gnats are abundant, and gnats only live in wet climates; since there are no geckos here, there must be no gnats and thus no wet climate.
Analysis: The argument is a bit of a logical train wreck involving two conditional errors. First, it assumes that because geckos are found where gnats are, the absence of geckos proves the absence of gnats—this is a classic 'denying the antecedent' flaw. Second, it assumes that because gnats need a wet climate, a lack of gnats proves the climate isn't wet. You should look for an answer that points out the author is treating a condition that is sufficient for geckos (gnats) as if it were necessary for them.
Conclusion: The local climate must not be wet.
Reasoning: Geckos are found wherever gnats are abundant, and gnats only live in wet climates; since there are no geckos here, there must be no gnats and thus no wet climate.
Analysis: The argument is a bit of a logical train wreck involving two conditional errors. First, it assumes that because geckos are found where gnats are, the absence of geckos proves the absence of gnats—this is a classic 'denying the antecedent' flaw. Second, it assumes that because gnats need a wet climate, a lack of gnats proves the climate isn't wet. You should look for an answer that points out the author is treating a condition that is sufficient for geckos (gnats) as if it were necessary for them.
Passage Stimulus
Passage Redacted
Unlock Full Passage9.The reasoning in the argument is flawed in that it
Correct Answer
B
B identifies the missing assumption: it presumes that all wet environments contain abundant gnats (wet -> abundant gnats). Without that, you cannot conclude not wet merely from not abundant gnats.
Upgrade Your Prep
Ready to go beyond free explanations?
LSAT Perfection is the #1 modern LSAT prep platform, trusted by thousands of students for comprehensive test strategies, advanced drilling, and full analytics on every PrepTest.
Detailed explanations for 59 PrepTests
Advanced drillset builder
Personalized analytics
Built-in Wrong Answer Journal